| unique_al((p0 ' + ax0) + p ' + ay), ∀ p, ay. unique_al(ax0 + p ' + ay) → ax0 + ay = [] ∨ ¬ (ax0 + ay).head.1 ∈ (ax0 + ay).tail ∧ unique_al((ax0 + ay).tail) ⊦ ¬ p0.1 ∈ ax0 ∧ ¬ p0.1 ∈ ay ∧ unique_al(ax0 + ay) |
⊦ unique_al(ay) ↔ ay = [] ∨ ¬ ay.head.1 ∈ ay.tail ∧ unique_al(ay.tail)
∀ p, ay. unique_al(ax0 + p ' + ay) → ax0 + ay = [] ∨ ¬ (ax0 + ay).head.1 ∈ (ax0 + ay).tail ∧ unique_al((ax0 + ay).tail), (p0 ' + ax0) + p ' + ay = [] ∨ ¬ ((p0 ' + ax0) + p ' + ay).head.1 ∈ ((p0 ' + ax0) + p ' + ay).tail ∧ unique_al(((p0 ' + ax0) + p ' + ay).tail) ⊦ ¬ p0.1 ∈ ax0 ∧ ¬ p0.1 ∈ ay ∧ unique_al(ax0 + ay)
Used terms: (p0 ' + ax0) + p ' + ay